SYNTHROID- levothyroxine sodium tablet

Levothyroxine is contraindicated in patients with uncorrected adrenal insufficiency since thyroid hormones may precipitate an acute adrenal crisis by increasing the metabolic clearance of glucocorticoids (see PRECAUTIONS). SYNTHROID is contraindicated in patients with hypersensitivity to any of the inactive ingredients in SYNTHROID tablets (See DESCRIPTION – Inactive Ingredients). In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage. In patients on a stable and appropriate replacement dosage, evaluate clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient’s clinical status. Absorption of orally administered T4 from the gastrointestinal (GI) tract ranges from 40% to 80%.

Effects on Bone Mineral Density

If the T4 is low and the TSH high, the diagnosis of permanent hypothyroidism is established, and levothyroxine therapy should be reinstituted. If the T4 and TSH levels are normal, euthyroidism may be assumed and, therefore, the hypothyroidism can be considered to have been transient. In this instance, however, the physician should carefully monitor the child and repeat the thyroid function tests if any signs or symptoms of hypothyroidism develop.

Adverse Reactions/Side Effects

• Treat patients with adrenal insufficiency with replacement glucocorticoids prior to initiating treatment with SYNTHROID see Contraindications (4).
• Hypersensitivity reactions to inactive ingredients have occurred in patients treated with thyroid hormone products.
• Foods that decrease absorption of levothyroxine, such as soybean infant formula, should not be used for administering levothyroxine sodium tablets (see PRECAUTIONS – Drug-Food Interactions).
• SYNTHROID is administered as a single daily dose, preferably one-half to one-hour before breakfast.
• Measure and evaluate unbound (free) hormone and/or determine the free-T4 index (FT4I) in this circumstance.

Synthroid is a medication that replaces hormones produced by your body. It is often prescribed to treat thyroid problems, but can be used to treat a variety of other medical issues, including diabetes, kidney and liver conditions, osteoporosis, problems with the adrenal or pituitary gland, and more. If you take it according to your doctor’s instructions, it is relatively safe, but you may need to manage some minor side effects. Get medical help right away if you notice any serious side effects, like an allergic reaction or chest pain, while taking synthroid. Initiate SYNTHROID therapy in this population at lower doses than those recommended in younger individuals or in patients without cardiac disease see DOSAGE AND ADMINISTRATION and Use In Specific Populations.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects. Notify your doctor if you experience serious side effects of Synthroid including rapid heartbeat, fluttering in your chest, or chest pain. Get medical help right away, if you have any of the symptoms listed above.

T4 absorption is increased by fasting, and decreased in malabsorption syndromes and by certain foods such as soybeans. In addition, many drugs and foods affect T4 absorption see Drug Interactions (7). In addition, many drugs and foods affect T4 absorption see DRUG INTERACTIONS. Myxedema coma is a life-threatening emergency characterized by poor circulation and hypometabolism and may result in unpredictable absorption of levothyroxine sodium from the gastrointestinal tract. Use of oral thyroid hormone drug products is not recommended to treat myxedema coma. Administer thyroid hormone products formulated for intravenous administration to treat myxedema coma.

• TSH may not normalize in some patients due to in utero hypothyroidism causing a resetting of pituitary-thyroid feedback.
• Absorption of orally administered T4 from the gastrointestinal (GI) tract ranges from 40% to 80%.
• This list is not complete and many other drugs may interact with levothyroxine.
• Levothyroxine is contraindicated in patients with untreated subclinical (suppressed serum TSH level with normal T3 and T4 levels) or overt thyrotoxicosis of any etiology and in patients with acute myocardial infarction.
• Consumption of certain foods may affect SYNTHROID absorption thereby necessitating adjustments in dosing see DOSAGE AND ADMINISTRATION.
• Serum digitalis glycoside levels may be decreased when a hypothyroid patient becomes euthyroid, necessitating an increase in the dose of digitalis glycosides (see Table 2).

Adequacy of therapy should be assessed by measuring serum free- T4 levels, which should be maintained in the upper half of the normal range in these patients. The major pathway of thyroid hormone metabolism is through sequential deiodination. Approximately eighty-percent of circulating T3 is derived from peripheral T4 by monodeiodination. The liver is the major site of degradation for both T4 and T3, with T4 deiodination also occurring at a number of additional sites, including the kidney and other tissues. Approximately 80% of the daily dose of T4 is deiodinated to yield equal amounts of T3 and reverse T3 (rT3).

If this SPL contains inactivated NDCs listed by the FDA initiated compliance action, they will be specified as such.

Patients with diabetes mellitus may require upward adjustments of their antidiabetic therapeutic regimens when treated with levothyroxine (see PRECAUTIONS – Drug Interactions). TSH may not normalize in some patients due to in utero hypothyroidism causing a resetting of pituitary-thyroid feedback. Assess compliance, dose of medication administered, and method of administration prior to increasing the dose of SYNTHROID see Warnings and Precautions (5.1) and Use in Specific Populations (8.4). Assess compliance, dose of medication administered, and method of administration prior to increasing the dose of SYNTHROID see WARNINGS AND PRECAUTIONS and Use In Specific Populations.

Cardiac Adverse Reactions In The Elderly And In Patients With Underlying Cardiovascular Disease

Careful inquiry should then be made regarding compliance, dose of medication administered, and method of administration prior to raising the dose of SYNTHROID. This may be a life-threatening emergency, therefore, symptomatic and supportive therapy should be instituted immediately. If not contraindicated (e.g., by seizures, coma, or loss of the gag reflex), the stomach should be emptied by emesis or gastric lavage to decrease gastrointestinal absorption. Activated charcoal or cholestyramine may also be used to decrease absorption. Central and peripheral increased sympathetic activity may be treated by administering β-receptor antagonists, e.g., propranolol, provided there are no medical contraindications to their use.

The majority of the levothyroxine dose is absorbed from the jejunum and upper ileum. The relative bioavailability of SYNTHROID tablets, compared to an equal nominal dose of oral levothyroxine sodium solution, is approximately 93%. T4 absorption is increased by fasting, and decreased in malabsorption syndromes and by certain foods such as soybean infant formula. In addition, many drugs and foods affect T4 absorption (see PRECAUTIONS – Drug Interactions and Drug-Food Interactions). Absorption of orally administered T4 from the gastrointestinal tract ranges from 40% to 80%. The majority of the SYNTHROID dose is absorbed from the jejunum and upper ileum.

Synthroid – Clinical Pharmacology

Although there has been a reported association between prolonged thyroid hormone therapy and breast cancer, this has not been confirmed. Patients receiving SYNTHROID for appropriate clinical indications should be titrated to the lowest effective replacement dose. Levothyroxine increases the response to oral anticoagulant therapy. Therefore, a decrease in the dose of anticoagulant may be warranted with correction of the hypothyroid state or when the SYNTHROID dose ashwagandha synthroid is increased.